Higher frequency of hepatic steatosis at CT among COVID-19-positive patients

Abstract

Purpose: Recent studies have demonstrated that obesity is significantly associated with increased disease severity, hospitalizations and mortality in COVID-19, with a potential role in the pathogenesis and prevalence in the new pandemic. The association with hepatic steatosis, however, a condition closely related to obesity within the spectrum of systemic metabolic dysfunctions, remains to be elucidated. We aimed to evaluate the frequency of hepatic steatosis as incidentally detected in chest CT examinations of COVID-19 positive patients in comparison to non-infected controls.

Methods: A retrospective study was performed with 316 patients (204 RT-PCR positive; 112 RT-PCR negative and chest CT negative). Steatosis was measured with placement of a single ROI in the right lobe of the liver (segments VI-VII) and defined as a liver attenuation value ≤ 40 HU.

Results: The frequency of hepatic steatosis was higher in the RT-PCR positive group in comparison to controls (31.9% vs. 7.1%, p < 0.001). Logistic linear regression analysis showed a 4.7 times odds of steatosis in the COVID-19 positive group as compared to controls after adjusting for age and sex (OR 4.698; 95% IC 2.12-10.41, p < 0.001).

Conclusion: A significantly higher prevalence of steatosis was found among COVID-19 positive individuals. These findings are in accordance with other recent studies linking obesity and COVID-19 infection, as there is an intricate relationship between liver steatosis, metabolic syndrome and obesity. Further studies are required to confirm if such association remains after accounting for multiple variables, as well as possible relationships with disease severity and worst clinical outcomes.

Keywords: COVID-19; CT; Hepatic steatosis; Liver.

Fig. 1

Demonstration of single ROI positioning and measurement—with an area of approximately 10 cm²—in the right liver lobe, preferentially between the segments VI and VII

Fig. 2

In this scheme, the fatty liver, demonstrated at the hepatocyte level, releases a cascade of systemic inflammatory events triggered by the virus, which may lead to a functional immune deficit. An uncontrolled immune response induces immunopathogenesis, resulting in lung tissue damage and multisystemic functional impairment. Therefore, obesity/steatosis may serve as a ‘’pre-activation state’’ for immune amplification by SARS-CoV2